1. Field of the Invention
The present invention generally relates to an indium oxide or an indium oxide based material, and a method for preparing the same, which is capable of increasing the electrical conductivity and light transmittance of the indium oxide or indium oxide based material, and in particular to an indium oxide or an indium oxide based material, and a method for preparing the indium oxide or the indium oxide based material by adding a carbon-containing compound thereto in order to increase its electrical conductivity and light transmittance.
2. The Prior Arts
The conventional indium oxide (In2O3) and the conventional indium oxide based material, such as indium tin oxide (ITO) and indium zinc oxide, are known to have high transparency and high electrical conductivity, and they are often used as a material for manufacturing the electrodes of the optoelectronic devices, such as the thin film transistor liquid crystal display (TFT-LCD), organic light emitting diodes (OLED), light emitting diodes (LED), and liquid crystal screens or touch screens of the electronic devices. Due to the rapid development of the flat panel displays (FPD), the improvement of the transparency and electrical conductivity of the conductive film made of indium tin oxide or its related materials is becoming a major topic of research in industry.
Typically, the indium oxides and the indium oxide based materials are prepared by solid-state reaction, chemical reaction, sol-gel method, physical vapour deposition, liquid phase deposition, and the like. In order to reduce the electrical resistivity and to increase the light transparency, the elements other than carbon are added to the indium oxides or the indium oxide based materials, or alternatively the indium oxide or indium oxide based materials are annealed in N2, O2, or H2 in a conventional method. In addition, indium oxides and the indium oxide based materials which are reduced electrical resistivity and increased light transparency are used to be made into the thin film electrodes. The method for forming an electrode thin film includes physical vapour deposition, physical vapour deposition, or sol-gel method. The method for adding the elements to the indium oxides and the indium oxide based materials includes solid-state reaction, chemical reaction, alloyed method, or doping method (such as diffusion, and ion implantation).
Using indium tin oxide as an example, the indium oxide (In2O3)/tin oxide (SnO2) powder is subjected to compounding, hot pressing, sintering, annealing, and other treatments to produce a sputtering target, and then the indium tin oxide film is formed on a substrate by sputtering using this sputtering target. In order to decrease the resistivity of the indium tin oxide film, the indium tin oxide film is subjected to annealing under the flow of nitrogen. However, the decreased resistivity is still not enough for practice use.